1. Field of the Invention
The present invention relates to a sheet package producing system. More particularly, the present invention relates to a sheet package producing system for producing a sheet package having a stack of sheets at a low cost and in a manner with compatibility to various sheet types.
2. Description Related to the Prior Art
X-ray films, printing sheets or other products of a sheet shape are shipped in a form of a sheet package by stacking those in a plurality. For example, continuous photosensitive material to be the X-ray film is prepared in a roll form, and cut into sheets of a regular length. The sheets are stacked in a plurality. A protective cover is loaded with the sheets to form a covered sheet stack. The protective cover is used for preventing the X-ray film from being bent or folded, and from being scratched. The covered sheet stacked is wrapped in a light-shielding packaging bag, and is enclosed tightly. The packaging bag is inserted in an outer box, and is shipped.
A producing system for the sheet package of the X-ray film include a slitting device, a cutting/stacking device, a bag packaging machine, a box forming device, a box packaging machine and a cardboard caser. The slitting device slits web of photosensitive material with a great width into continuous sheets with a width of a sheet size. The cutting/stacking device cuts the continuous sheets into the sheets, and stacks the sheets in the predetermined number. The bag packaging machine closes a bag by sealing in a pillow shape or sealing three edges. The box forming device produces the outer box for containing the X-ray film. The box packaging machine inserts the X-ray film into the outer box. The cardboard caser inserts the outer box with the X-ray film into a cardboard box.
The bag packaging machine, which is disposed downstream in the producing system for the sheet package, operates for one time while the cutting/stacking device creates a predetermined number of the sheets by cutting. It is necessary to change over the bag packaging machine rapidly specifically for production at the sheet size being different, or in a multi-type manner. Therefore, recently used types of the bag packaging machine have had a gradual tendency of enlargement in the size, raise in complexity, and raise in performance. There is a suggestion in JP-A 5-051021 to install a plurality of the cutting/stacking device in an upstream station. Paths of the sheets from the cutting/stacking device are joined up as a single path at the bag packaging machine.
The number of the sheet size of the X-ray film is small. It is general that the producing system is structured in a specialized manner for a predetermined size of the sheet size. In the producing system for the X-ray film, the protective cover is pre-bent at a target end portion to be folded. The sheets are stacked on the protective cover after the pre-bending. Then the protective cover is folded before forming the sheet package.
In the producing system including the cutting/stacking device in the plurality, the ability of processing of the bag packaging machine is considered as minimum ability. If a difference occurs between the ability and that required in view of profits, it requires a remarkably large space for installation, and also expenses for investment. Furthermore, the facilities with the producing system are hard to maintain in a stable state. This is the case typically because the personnel having high skill in monitoring and handling the producing system cannot be easily employed.
For multi-type production, frequent changes are inevitable in the bag packaging machine about the sheet size and the type. It is likely that the sheet size or the type is different between the bag packaging machine and the cutting/stacking device operating at the same time. The X-ray film different in the sheet size or the type at the time of processing in the bag packaging machine is stored in a temporary manner. This results in precise administration of addresses of the X-ray film in the reservoir, precision in planning the production with judgement in priority of plural processes, precision in the administration of the production in relation to instructions, monitoring of achievements and the like, and complexity in systemizing the administration of information. To reserve the X-ray film requires sufficient spaces, which is likely to be inconsistent to rapidity in shipment of the X-ray film.
The producing system specialized for the X-ray film has low compatibility with the producing system for products other than the X-ray film. If a new product of the X-ray film is developed, the producing system cannot be applied in the initially specialized structure. A problem arises in a short period of using the same facilities of the producing system.